As packaging materials, much used are materials each having a structure in which a polyolefin resin film is laminated as a sealant layer on the top surface of a barrier layer such as an aluminum foil. A packaging bag can be formed by mutually laminating and heat sealing the sealant layers of two sheets of a packaging material. In general, when a sealant layer is laminated on a barrier layer, an adhesive layer (also referred to as a primer, an anchor coat or the like) is disposed. In a packaging bag formed with a packaging material having such a structure, a volatile substance such as menthol or naphthalene, a content containing a fragrant component or a medicinal component, a secondary battery containing a solid organic electrolyte or the like is packaged, as the case may be. In such a case, there occurs a problem that during storage in the bag, such a substance or such a component may swell or dissolve the adhesive layer between the barrier layer and the sealant layer, and hence the adhesion strength between the barrier layer and the sealant layer is degraded with time, or both layers are detached from each other (delamination). For the purpose of solving this problem, improvements have been made as disclosed, for example, in JP-A-11-254595 and JP-A-2001-32221. However, depending on the types of the contents, the content resistance of the adhesive layer against the content cannot be said to be sufficient.